Baleares Station (Site 57)

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Zooplankton vertical distribution in waters of the Mallorca shelf: autumn and summer

The zooplankton vertical distribution (VD) has been studied in two areas of the Mallorca shelf during December 2009 and July 2010. Five and eight, depth levels were sampled at day/night by using BIONESS an MOCNESS multinet. 17 zooplankton groups were found, where copepods were the most abundant (70%), being responsible of the whole zooplankton VD pattern. Copepod high diversity was found in both months (4.3 bits and 3.3bits) and more than 88 species identified. The highest diversity was found in deeper waters (90-120 m) in the afternoon than during day time (0-90m) in December but in July, always found at deeper layer (100-150 m), suggesting that epipelagic and mesopelagic copepods co-occurred, and diel changes induced the increased diversity. Clausocalanus arcuicornis (13%), Nannocalanus minor (10%) and Pleuromamma (P. gracilis and P. abdominalis, 8% and 6%) were the most abundant. However others such as Acartia clausi and Clausocalanus furcatus appeared in December and Centropages typicus, Euchaeta acuta and Lucicutia flavicornis in July. In relation to water conditions the VD exhibited different patterns with a higher difference in autumn between the two sites than in summer when the zooplankton was concentrated around the FMD. Species like N. minor, A. clausi, as well as all Clausocalanus and Oithona did not show clear vertical movements; but others showed weak, intermediate or strong migration, such as Lucicutia, Euchaeta and Pleuromamma which exhibited clear nocturnal VD. The importance of these species in the active carbon transfer is discussed in this oligotrophic area of the central western Mediterranean

Orden Calanoida

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North Atlantic climate control on plankton variability in the Balearic Sea, western Mediterranean

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11 Year zooplankton time-series related to North Atlantic climate changes in waters of the Balearic Sea (western Mediterranean)

Workshop I: Climate impact on ecosystem dynamics of marginal and semi-enclosed sea

Annual cycle of zooplankton biomass, abundance and species composition in the neritic area of the Balearic Sea, western Mediterranean

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Phytoplankton composition in a neritic area of the Balearic Sea (Western Mediterranean)

From September 2000 to September 2001 the concentration of chlorophyll a, and the abundance and composition of the phytoplanktonic community was studied in a neritic station of the Mallorca Channel (Western Mediterranean). Sampling was performed approximately every 12 days. Chlorophyll a concentration and phytoplankton abundance reached maxima of 1.79 mg L2l and 352 cells mL21, respectively. It was a relatively productive period, as a result of the high convective mixing in winter and the prevalence of northern waters during most of the cycle. Phytoplankton proliferations (chlorophyll-a concentration .1 mg L21) were detected in January, February, March and June. Those blooms mainly happened under the influence of northern waters, with the exception of the February proliferation, when mixing conditions were found. During bloom conditions it highlights the presence of coccolithophores as proliferation precursors. During no-bloom situations the phytoplankton community was mainly constituted by nanoplanktonic flagellated forms. The Winter Mixing period was dominated by different groups of nanoflagellates, including coccolithophores, undetermined flagellates and dinoflagellates. However, in the most oligotrophic conditions (from April until November) dinoflagellates were clearly dominant, except in the DCM in summer where diatoms prevailed.Versión del edito